Remove SPS profiler.

- Conditionals and code blocks. (MOZ_ENABLE_PROFILER_SPS)
- Stub out several profiler-only functions.

xpcom/threads/ThreadStackHelper.h

@@ -23,27 +23,6 @@
 #include <mach/mach.h>
 #endif
 
-// Support pseudostack on these platforms.
-#if defined(XP_LINUX) || defined(XP_WIN) || defined(XP_MACOSX)
-#  ifdef MOZ_ENABLE_PROFILER_SPS
-#    define MOZ_THREADSTACKHELPER_PSEUDO
-#  endif
-#endif
-
-#ifdef MOZ_THREADSTACKHELPER_PSEUDO
-#  define MOZ_THREADSTACKHELPER_NATIVE
-#  if defined(__i386__) || defined(_M_IX86)
-#    define MOZ_THREADSTACKHELPER_X86
-#  elif defined(__x86_64__) || defined(_M_X64)
-#    define MOZ_THREADSTACKHELPER_X64
-#  elif defined(__arm__) || defined(_M_ARM)
-#    define MOZ_THREADSTACKHELPER_ARM
-#  else
-     // Unsupported architecture
-#    undef MOZ_THREADSTACKHELPER_NATIVE
-#  endif
-#endif
-
 namespace mozilla {
 
 /**
@@ -63,29 +42,10 @@ public:
 
 private:
   Stack* mStackToFill;
-#ifdef MOZ_THREADSTACKHELPER_PSEUDO
-  const PseudoStack* const mPseudoStack;
-#ifdef MOZ_THREADSTACKHELPER_NATIVE
-  class ThreadContext;
-  // Set to non-null if GetStack should get the thread context.
-  ThreadContext* mContextToFill;
-  intptr_t mThreadStackBase;
-#endif
-  size_t mMaxStackSize;
-  size_t mMaxBufferSize;
-#endif
 
   bool PrepareStackBuffer(Stack& aStack);
   void FillStackBuffer();
   void FillThreadContext(void* aContext = nullptr);
-#ifdef MOZ_THREADSTACKHELPER_PSEUDO
-  const char* AppendJSEntry(const volatile StackEntry* aEntry,
-                            intptr_t& aAvailableBufferSize,
-                            const char* aPrevLabel);
-#endif
-#ifdef MOZ_THREADSTACKHELPER_NATIVE
-  void GetThreadStackBase();
-#endif
 
 public:
   /**